Diagnostic Procedures
1. Checking Additional Diagnostic Trouble Codes
- Read diagnostic trouble codes.
Any other diagnostic trouble codes?
YES
Go to step 4.
NO
Go to step 2.
2. Checking Additional Diagnostic Trouble Codes
Continue fault diagnosis for the diagnostic trouble code concerned.
Go to Diagnostic Trouble Code Index
3. Checking The Battery Voltage
Part 1 Of 2:
Part 2 Of 2:
Take a voltage reading between B+ and ground.
The reading should be 12 V - 14 V
Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
Is the function correct?
NO
Go To Step 4
YES
Go To Step 5
4. Checking The Battery Voltage
Check the battery
When repair is complete:
Go to Step 13
5. Check The Control Modules's Power Supply
Unplug the connector.
Control module, TCM502
Connect test lamp 86 11 857 to pin 20 of the control module's female connector and a good ground.
Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct?
NO
Go To Step 6
YES
Go To Step 7
6. Rectifying The Lead
Repair the lead between pin 16 in the female connector and the fuse 12 in the dashboard main fuse board.
When repair is complete:
Go to step 13
7. Check The Control Module Power Supply
Connect test lamp 86 11 857 between pin 21 of the control module female connector and a good grounding point.
Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct?
NO
Go To Step 8
YES
Go To Step 9
8. Rectifying The Lead
Repair the lead between pin 1 in the female connector and the fuse B in the dashboard main fuse board.
When repair is complete:
Go to step 13
9. Check The Control Module Power Supply
Connect test lamp 86 11 857 between pin B+ and pin 42 of the control module female connector.
Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct?
NO
Go To Step 10
YES
Go To Step 11
10. Rectifying The Lead
Repair the lead between pin 31 in the female connector and grounding point G43.
When repair is complete:
Go to step 13
11. Check The Control Module Power Supply
Connect test lamp 86 11 857 between B+ and pin 21 of the control module female connector.
Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct?
NO
Go To Step 12
YES
Go To Step 13
12. Rectifying The Lead
Repair the lead between pin 32 in the female connector and grounding point G43.
When repair is complete:
Go to step 13
13. Final Check
- Clear the diagnostic trouble codes in all systems.
Carry out a drive cycle:
- Drive the car at varying engine loads and engine rpm for five minutes.
Evaluate the drive cycle,
- Check that the diagnostic trouble code has not recurred
Is the function correct?
NO
Go To Step 14
YES
Go To Step 15
14. Final Check
See Before changing a control module, refer to General Fault Diagnosis.
- Diagnosis for this fault code is complete.
15. Final Check
The steps taken to correct the fault were correct.
- Diagnosis is complete.